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STARKE, Fla. (AP) -

A man convicted of abducting and killing a Miami couple and later stabbing a prison guard to death is set for execution at Florida State Prison.

Askari Abdullah Muhammad, previously known as Thomas Knight, is scheduled to die by lethal injection Tuesday.

The 62-year-old Muhammad was first condemned to die for the 1974 abduction and killings of Sydney and Lillian Gans of Miami. He was sentenced to die again for killing corrections officer Richard Burke in 1980 using a sharpened spoon.

His execution has been delayed for so long because of numerous appeals and rulings, including a 1987 federal appeals court tossing out his death sentence because he hadn't been allowed to put character and background witnesses on the stand during the penalty phase.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.